Painted white roof drops house temps 8-10 degrees

tasdbois · 07-26-10, 04:05 PM

Interesting. I wonder how less visually intrusive alternatives compare. Say a radiant barrier with increased attic airflow.

TimJFowler · 07-26-10, 05:20 PM

According to the FSEC (Florida State Energy Center) a radiant barrier in the attic can reduce home cooling needs by +/- 9% FSEC-CR-1231-01. A reflective white roof can reduce cooling needs by 18-35% FSEC-CR-1220-00. Those improvements include results for several homes that already had powered attic ventilation.

Thanks to BuilditSolar.com Passive Cooling Techniques for both links.

I've been very pleased with our cool roof (not white, but a good Solar Reflectance Index). We're midway through our second summer with the cool roof and it has made a big difference in our comfort level.

I'm still looking to improve our home's passive cooling, but the roof definitely helped during a recent heatwave. We're Having a Heat Wave, a Tropical Heat Wave | EcoNewMexico.com

tomboy mom · 07-04-11, 03:56 PM

Quote:

Originally Posted by tasdbois

Interesting. I wonder how less visually intrusive alternatives compare. Say a radiant barrier with increased attic airflow.

i have added radiant barriers to both my attics. omg. talk about work! it all sounds good until you're sliding through an attic with a flashlight in your hand, a mask on your face and a backpack full of stapling supplies and attempting to pull and kick an unruly roll of radiant barrier through while balancing on the 2x4's. (word to the wise--take a phone in case you need to ask for something.)

did it help? YES! absolutely had more impact on temperature than anything else short term.

we don't need need to turn on central air until the outside temperature is about 105--closer to 110 if we have done everything perfectly that day. without the radiant barrier i don't think that would be possible.

however, if painting the roof white would be as effective i would gladly do that instead and not really care about what it looks like.

07-26-10, 05:20 PM	#2
TimJFowler Apprentice EcoRenovator Join Date: Dec 2008 Location: Santa Fe, NM Posts: 184 Thanks: 9 Thanked 12 Times in 11 Posts	According to the FSEC (Florida State Energy Center) a radiant barrier in the attic can reduce home cooling needs by +/- 9% FSEC-CR-1231-01. A reflective white roof can reduce cooling needs by 18-35% FSEC-CR-1220-00. Those improvements include results for several homes that already had powered attic ventilation. Thanks to BuilditSolar.com Passive Cooling Techniques for both links. I've been very pleased with our cool roof (not white, but a good Solar Reflectance Index). We're midway through our second summer with the cool roof and it has made a big difference in our comfort level. I'm still looking to improve our home's passive cooling, but the roof definitely helped during a recent heatwave. We're Having a Heat Wave, a Tropical Heat Wave \| EcoNewMexico.com __________________ - DIY Adventures in Applied Sustainability - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Last edited by TimJFowler; 07-26-10 at 05:29 PM.. Reason: added note about attic ventilation

07-26-10, 04:05 PM	#1
tasdbois Lurking Renovator Join Date: Oct 2008 Location: Mirabel, QC Posts: 28 Thanks: 0 Thanked 0 Times in 0 Posts	Interesting. I wonder how less visually intrusive alternatives compare. Say a radiant barrier with increased attic airflow.